A Sliding Mode Control Based Stabilization Method for Directional Rotary Steering Tool-Face

When the directional rotary steering system works in the state of maintaining the tool face angle, the use of PID control mode will lead to a large swing angle of the tool face angle of the directional rotary steering system. In order to reduce the swing amplitude of the tool face angle, based on the PID position control and the angle position error sliding mode control strategy, the exponential synovial control function is established. The simulation results show that the fast and accurate tool face angle tracking is achieved through the closed-loop control of the angle position. The paper provides an implementation method for the research of directional rotary steering system

Three Capsular Polysaccharide Synthesis-Related Glucosyltransferases, GT-1, GT-2 and WcaJ, Are Associated With Virulence and Phage Sensitivity of Klebsiella pneumoniae

Klebsiella pneumoniae (K. pneumoniae) spp. are important nosocomial and community-acquired opportunistic pathogens, which cause various infections. We observed that K. pneumoniae strain K7 abruptly mutates to rough-type phage-resistant phenotype upon treatment with phage GH-K3. In the present study, the rough-type phage-resistant mutant named K7RR showed much lower virulence than K7. Liquid chromatography-tandem mass spectrometry (LC-MS-MS) analysis indicated that WcaJ and two undefined glycosyltransferases (GTs)- named GT-1, GT-2- were found to be down-regulated drastically in K7RR as compared to K7 strain. GT-1, GT-2, and wcaJ are all located in the gene cluster of capsular polysaccharide (CPS). Upon deletion, even of single component, of GT-1, GT-2, and wcaJ resulted clearly in significant decline of CPS synthesis with concomitant development of GH-K3 resistance and decline of virulence of K. pneumoniae, indicating that all these three GTs are more likely involved in maintenance of phage sensitivity and bacterial virulence. Additionally, K7RR and GT-deficient strains were found sensitive to endocytosis of macrophages. Mitogen-activated protein kinase (MAPK) signaling pathway of macrophages was significantly activated by K7RR and GT-deficient strains comparing with that of K7. Interestingly, in the presence of macromolecular CPS residues (>250 KD), K7(ΔGT-1) and K7(ΔwcaJ) could still be bounded by GH-K3, though with a modest adsorption efficiency, and showed minor virulence, suggesting that the CPS residues accumulated upon deletion of GT-1 or wcaJ did retain phage binding sites as well maintain mild virulence. In brief, our study defines, for the first time, the potential roles of GT-1, GT-2, and WcaJ in K. pneumoniae in bacterial virulence and generation of rough-type mutation under the pressure of bacteriophage

A Sliding Mode Control Based Stabilization Method for Directional Rotary Steering Tool-Face

When the directional rotary steering system works in the state of maintaining the tool face angle, the use of PID control mode will lead to a large swing angle of the tool face angle of the directional rotary steering system. In order to reduce the swing amplitude of the tool face angle, based on the PID position control and the angle position error sliding mode control strategy, the exponential synovial control function is established. The simulation results show that the fast and accurate tool face angle tracking is achieved through the closed-loop control of the angle position. The paper provides an implementation method for the research of directional rotary steering system

Bfp net: balanced feature pyramid network for small apple detection in complex orchard environment

Despite of significant achievements made in the detection of target fruits, small fruit detection remains a great challenge, especially for immature small green fruits with a few pixels. The closeness of color between the fruit skin and the background greatly increases the difficulty of locating small target fruits in the natural orchard environment. In this paper, we propose a balanced feature pyramid network (BFP Net) for small apple detection. This network can balance information mapped to small apples from two perspectives: multiple-scale fruits on the different layers of FPN and a characteristic of a new extended feature from the output of ResNet50 conv1. Specifically, we design a weight-like feature fusion architecture on the lateral connection and top-down structure to alleviate the small-scale information imbalance on the different layers of FPN. Moreover, a new extended layer from ResNet50 conv1 is embedded into the lowest layer of standard FPN, and a decoupled-aggregated module is devised on this new extended layer of FPN to complement spatial location information and relieve the problem of locating small apple. In addition, a feature Kullback-Leibler distillation loss is introduced to transfer favorable knowledge from the teacher model to the student model. Experimental results show that of our method reaches 47.0%, 42.2%, and 35.6% on the benchmark of the GreenApple, MinneApple, and Pascal VOC, respectively. Overall, our method is not only slightly better than some state-of-the-art methods but also has a good generalization performance

Method to evidence hypernuclear halos from a two-target interaction cross section measurement

We present a two-target measurement method to determine the interaction cross section of hypernuclei with a target nucleus. The method allows to extract from two independent measurements the production cross section of a given hypernucleus as well as its interaction cross section on a specific target. The latter is then further analyzed to deduce the matter radius of the hypernucleus. The sensitivity of the method has been investigated for the specific case of the lightest hyperhalo candidate hypertriton ($$^3_\Lambda$$H) produced from $$^{12}$$C+$$^{12}$$C collisions at 1.9 GeV/nucleon. Furthermore, its feasibility is demonstrated by detailed simulations for realistic experimental conditions at GSI/FAIR, using a dedicated HYDRA (HYpernuclei Decay at R$$^3$$B Apparatus) time-projection chamber prototype. A precision of 15% or better in the interaction cross section can be achieved, allowing an extraction of the unknown $$^3_\Lambda$$H matter radius and assessing its halo or non-halo character

The Characteristics and Genome Analysis of vB_AviM_AVP, the First Phage Infecting <i>Aerococcus viridans</i>

Aerococcus viridans is an opportunistic pathogen that is clinically associated with various human and animal diseases. In this study, the first identified A. viridans phage, vB_AviM_AVP (abbreviated as AVP), was isolated and studied. AVP belongs to the family Myoviridae. AVP harbors a double-stranded DNA genome with a length of 133,806 bp and a G + C content of 34.51%. The genome sequence of AVP showed low similarity (&lt;1% identity) to those of other phages, bacteria, or other organisms in the database. Among 165 predicted open reading frames (ORFs), there were only 69 gene products exhibiting similarity (&#8804;65% identity) to proteins of known functions in the database. In addition, the other 36 gene products did not match any viral or prokaryotic sequences in any publicly available database. On the basis of the putative functions of the ORFs, the genome of AVP was divided into three modules: nucleotide metabolism and replication, structural components, and lysis. A phylogenetic analysis of the terminase large subunits and capsid proteins indicated that AVP represents a novel branch of phages. The observed characteristics of AVP indicate that it represents a new class of phages